Testing up to four cellular/communications devices in parallel
The wireless industry is now producing some 1.5 billion handsets per year with an average test time of 4 minutes/device. For those who are counting, that’s 360 billion seconds worth of testing time per year. Making matters even worse, typical manufacturing test costs are as much as 5% to 10% of the total cost of the end product.
Enough is enough, says LitePoint, a maker of wireless-manufacturing test systems. With the introduction of its IQxstream test system, the company is hoping to leverage parallelism to make a large dent in test time and cost for high-volume 3G/4G cellular devices (see video). The system-level production tester will, the company says, make inroads in one of the areas that are the biggest time-waster in production test of wireless handsets, namely the device-under-test (DUT) control portion of the cycle.
The next wave of smart phones, netbooks, and mobile Internet devices will feature 4G wireless broadband radios and standards such as Long-Term Evolution (LTE). These devices aren’t dominated by voice communications, but as in the case of Apple’s forthcoming iPad, they’ll spend most of their time trafficking in broadband data protocols (see “Success Of iPad Is All About Software”).
Thus, today’s 3G and 4G handsets and other portable devices include multiple radios representing numerous standards. Traditional test methods involve attaching dummy loads to the handsets and testing the various radios one at a time in serial fashion. It will do so by testing up to four cellular/communications devices (see the figure) in parallel. “Testing the four in parallel takes 15 seconds,” says Spiros Bouas, LitePoint’s chief operating officer. “Testing them serially takes 60 seconds.”
The IQxstream system is designed to reduce per-device test time and cost thanks to its parallel architecture. A 100-MHz capture capability enables the system to test LTE adjacent channel leakage ratios (ACLR) in one five-channel capture. The IQxstream system performs test analysis, which has traditionally also been accomplished in sequential fashion, in parallel using a proprietary multicore processor. The result is what Bouas terms “parallelism cubed” due to the system’s ability to test multiple DUTs even as it simultaneously tests multiple radio standards. “We’re offering double the throughput for less than double the capital cost of multiple standalone testers,” says Bouas.
Further, all four of the system’s test ports allow for true multiple-input multiple-output (MIMO) testing. LTE devices, by design, will use 1x2 and 2x2 MIMO technology. IQxstream systems are designed to test four such devices, in near parallel, including those with up to two transmitters and two receivers.
The IQxstream system can test a total of nine standards: GSM, EDGE, CDMA One, W-CDMA, HSPA, HSPA+, CDMA-2000, EV-DO, and LTE. Current plans call for first deliveries during the summer of 2010. Pricing will be announced with more detailed specs during the second quarter of 2010.